For me, my problem with MorphOS users pushing their OS isn't the way it's done, it's the timing.
In a hypothetical thread, for instance, entitled "I want an AmigaOS system and don't know what to buy!", a reasoned discussion of the MOS/AOS/AROS options is welcome.
In another hypothetical thread which may be entitled "New AmigaOne 500 released", going on about how it's overpriced and how MOS is better and yada yada yada is not welcome. If you don't like AOS 4 - fine, but don't bother us with your yelling, keep it to a thread that's about MOS.
Inidentally, I'm not hiding in any shell, despite being primarily an AOS user. I also occasionally use and develop for MOS and AROS too. I just find AOS is the best for me.
And if you feel sorry for me for spending money on brand new hardware for my hobby - don't. I'm not three years old, I know what I'm buying!
So, being AmigaOS user I am entitled to warn everyone to not buy AmigaOS =P